Method of selecting a golf club

ABSTRACT

A method for selecting a golf club suitable for a golfer includes step (a) of obtaining at least one of head speed and hit-ball data (initial velocity, launch angle, backspin, side spin, and travel distance) when a golfer hits a golf ball with a golf club; step (b) of obtaining ideal hit-ball data of the golfer on the basis of the head speed and hit-ball data obtained in step (a); step (c) of providing a guideline for showing a way of modifying the golf club used in step (a) in order to obtain hit-ball data close to the ideal hit-ball data obtained in step (b); and step (d) of obtaining head speed and hit-ball data when the golfer hits a golf ball with a golf club for trial hit which matches, to the extent possible, the guideline provided in step (c).

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a method for selecting a golf club suitable for a golfer, and more particularly, to a golf club selecting method which is effectively used in particular for selection of a custom-made club; i.e., a golf club having specifications different from those of ready-made clubs.

[0003] 2. Description of the Related Art

[0004] Conventionally, a golf club suitable for a golfer has been selected by a method utilizing an apparatus that obtains data regarding a locus of a swing of the golfer and data regarding a hit ball, by use of, for example, a CCD camera.

[0005] Specifically, such an apparatus is installed in a golf shop, etc.; and, on the basis of data obtained by use of the apparatus, a clerk or the like recommends to the golfer a golf club on the market.

[0006] However, the above-described conventional golf club selecting method involves a drawback in that a golfer cannot determine whether a recommended golf club is really suitable for the golfer unless he or she purchases the recommended golf club and actually hits balls with the golf club. Moreover, for some golfers, suitable golf clubs cannot be found from golf clubs (ready-made golf clubs) sold on the market, and ordering golf clubs having specifications suitable for them is better.

SUMMARY OF THE INVENTION

[0007] The present invention has been accomplished in view of the foregoing, and an object of the present invention is to provide a golf club selecting method which enables a golfer to properly select a golf club suitable for the golfer after actually hitting a ball with the golf club, even when a custom-made club is suitable for the golfer.

[0008] In order to accomplish the above-described purposes, the present invention provides a method for selecting a golf club suitable for a golfer, comprising the steps of:

[0009] (a) obtaining at least one of head speed and hit-ball data when a golfer hits a golf ball with a golf club;

[0010] (b) obtaining ideal hit-ball data of the golfer on the basis of said at least one of head speed and hit-ball data obtained in step (a);

[0011] (c) providing a guideline for showing a way of modifying the golf club used in step (a) in order to obtain hit-ball data close to the ideal hit-ball data obtained in step (b), the guideline being provided on the basis of said at least one of head speed and hit-ball data obtained in step (a) and the ideal hit-ball data obtained in step (b);

[0012] (d) obtaining at least one of head speed and hit-ball data when the golfer hits a golf ball with a golf club for trial hit which matches, to the extent possible, the guideline provided in step (c); and

[0013] (e) displaying one or more items selected from said at least one of head speed and hit-ball data obtained in step (a), the ideal hit-ball data obtained in step (b), the guideline provided in step (c), and said at least one of head speed and hit-ball data obtained in step (d).

[0014] According to the golf club selecting method of the present invention, a recommended golf club which enables obtainment of hit-ball data close to the ideal hit-ball data obtained in step (b) is displayed in step (c) together with the golf club (e.g., a golf club that the golfer uses currently) used in step (a) and serving as a reference golf club, and its related data are displayed in step (e) together with corresponding data of the reference golf club. On the basis of the displayed data, a club for trial hit is selected or prepared. In step (d) the golfer actually hits a golf ball by use of the club for trial hit, which trial hit enables the golfer to check whether hit-ball data closer to the ideal hit-ball data have been obtained. Moreover, in the case of a golfer for whom golf clubs sold on the market are not suitable, the golfer can confirm that a previously-prepared golf club for trial hit is suitable for the golfer through actually hitting a golf ball by use of the golf club for trial hit (a golf club for trial hit having specifications different from those of ready-made golf clubs). As a result, even an amateur golfer can order and purchase, without anxiety, a custom-made club which includes a combination of a club head, a shaft, and, in some cases, a grip, determined to be suitable for the golfer, but which the golfer would not usually be confident enough to purchase, by virtue of the golfer being able to confirm the effects of the golf club through trial hit.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a schematic diagram of an example of the system used for the embodiment of the method for selecting a golf club according to the present invention;

[0016]FIG. 2 is a view showing the arrangement of devices of the system of FIG. 1;

[0017]FIG. 3 is a timing chart illustrating operation of the system of FIG. 1;

[0018]FIG. 4 is a view showing a monitor screen of the system of FIG. 1; and

[0019]FIG. 5 is a diagram of an example sheet produced by the printing means of the system of FIG. 1.

DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENT

[0020] The present invention will now be described in further detail. In the present invention, first, in step (a), a golfer is requested to hit a golf ball by use of a golf club, and at least one of head speed and hit-ball data is obtained at that time. The term “hit-ball data” means various numerical data in relation to a golf ball at the time the golfer hits the golf ball. Examples of the hit-ball data include initial velocity, launch angle, backspin, side spin, and travel distance of a hit ball.

[0021] In the present invention, at least one of head speed, initial velocity, launch angle, backspin, side spin, and travel distance is selected as the above-described at least one of head speed and hit-ball data; preferably, all these values are obtained. When all values of the above-described items are obtained, numerous data regarding the golfer who has hit balls can be obtained. Notably, as shown in an embodiment to be described later, the above-described head speed, initial velocity, launch angle, backspin, and side spin can be measured by use of a measurement apparatus; and the travel distance can be calculated from the initial velocity, launch angle, backspin, and side spin.

[0022] A golf club which the golfer has used for play and which is therefore familiar to the player is preferably used as the golf club to be used by the golfer to hit a golf ball. This enables acquisition of proper head speed and hit-ball data, to thereby enable more proper selection of a golf club for trial hit suitable for the golfer.

[0023] In the present invention, in subsequent step (b), ideal hit-ball data of the golfer are calculated on the basis of said at least one of head speed and hit-ball data obtained in the above-described manner. At least one of ideal initial velocity, ideal launch angle, ideal backspin, ideal side spin, and ideal travel distance is selected as the ideal hit-ball data; preferably, all these values are selected. When all values of the above-described items are obtained, many data useful for selection of a club can be obtained. The ideal hit-ball data can be obtained through calculation, and a portion of the ideal hit-ball data can be set in advance. For example, the ideal initial velocity, ideal launch angle, and ideal backspin can be obtained from a head speed at the time the golfer actually hits a golf ball, in accordance with predetermined calculation expression. Further, the ideal side spin may be set to zero. Further, the ideal travel distance can be calculated from the ideal initial velocity, ideal launch angle, ideal backspin, and ideal side spin, in accordance with predetermined calculation expression.

[0024] In the present invention, in subsequent step (c), on the basis of said at least one of head speed and hit-ball data obtained in step (a) and the ideal hit-ball data obtained in step (b), a guideline is provided for showing a manner of modifying the golf club used in step (a), in order to obtain hit-ball data close to the ideal hit-ball data obtained in step (b). Although no limitation is imposed on the details of the guideline, examples of the guideline include the following.

[0025] (i) When a launch angle obtained in step (a) differs from an ideal launch angle obtained in step (b), there is provided a guideline that recommends changing the loft angle by a predetermined amount; e.g., a guideline that recommends increasing the loft angle by 1°.

[0026] (ii) When a backspin obtained in step (a) differs from an ideal backspin obtained in step (b), there is provided a guideline that recommends changing the loft angle by a predetermined amount; e.g., a guideline that recommends decreasing the loft angle by 10.

[0027] (iii) When a side spin obtained in step (a) differs from an ideal side spin obtained in step (b), there is provided a guideline that recommends changing the face angle by a predetermined amount; e.g., a guideline that recommends changing the face angle by 1° toward the close side.

[0028] (iv) On the basis of a head speed obtained in step (a), there is provided a guideline that recommends changing the hardness of the shaft; e.g., a guideline that recommends changing the hardness of the shaft from S flex to R flex.

[0029] In the present invention, in subsequent step (d), at least one of head speed and hit-ball data is obtained when the golfer hits a golf ball with at least one golf club for trial hit which matches to the extent possible the guideline provided in step (c). The golf club for trial hit may be selected manually by a person or automatically by use of club selection means for selecting a golf club for trial hit on the basis of the specifications of the golf club used in step (a) and the guideline provided in step (c). Further, at least one of initial velocity, launch angle, backspin, side spin, and travel distance is selected as the above-described hit-ball data; preferably, all these values are obtained. When all values of the above-described items are obtained, effects of a selected golf club for trial hit can be checked by use of a large number of data items. As described above, the present invention enables a golfer to check effects of a custom-made club which includes a combination of a club head, a shaft, and, in some cases, a grip, by hitting golf balls by use of a corresponding golf club for trial hit. Accordingly, in the present invention, preferably, a large number of golf clubs for trial hit having various specifications differing from those of golf clubs on the market are prepared.

[0030] In the present invention, in step (e), one or more items selected from said at least one of head speed and hit-ball data obtained in step (a), the ideal hit-ball data obtained in step (b), the guideline provided in step (c), and said at least one of head speed and hit-ball data obtained in step (d) are displayed on a monitor or the like. Limitation is imposed on neither the time at which step (e) is performed nor the number of times step (e) is performed. For example, step (e) may be performed only one time after completion of the remaining steps (a) to (d), or may be performed after completion of each of the steps (a) to (d), whereby step (e) is performed a plurality of times.

[0031] Preferably, the golf club selecting method according to the present invention further comprises the step of providing specifications of an ideal golf club which enables obtainment of hit-ball data close to the ideal hit-ball data obtained in step (b), the specifications being provided on the basis of the specifications of the golf club used in step (a) and the guideline provided in step (c). This enables a golfer to know specifications of a golf club ideal for the golfer, and also enables the golfer to purchase a golf club sold on the market whose specifications substantially match the specifications of the ideal golf club, or to order a custom-made golf club which has the same specifications as the ideal golf club when none of golf clubs on the market matches the ideal golf club in terms of specifications. In this case, the specifications of the ideal golf club include total length, balance, and total weight of the golf club; loft angle, face angle, and lie angle of the club head; hardness and feeling of the shaft; and thickness of the grip.

[0032] In the present invention, when the step for showing the specifications of the ideal golf club is provided, the golf club selecting method may further comprise the step of printing out the specifications of the ideal golf club on a sheet of paper that is to become a post card. This enables a golfer to easily order a custom-made club by use of the post card. Further, the golf club selecting method according to the present invention may comprise the step of outputting the specifications of the ideal golf club to a floppy disk. This enables a golfer to easily order a custom-made club by use of the floppy disk.

[0033] For example, a custom-made club can be ordered through an operation of transmitting the data stored in the floppy disk directly to a golf-club manufacturer via a telephone line (the Internet).

[0034] An embodiment of the present invention will now be described with reference to the drawings. FIG. 1 is a schematic diagram showing an example system which is used for practicing the golf club selecting method according to the present invention. The system includes golf ball setting means 12 for setting a golf ball 11 in place; specifically a tee for placing the golf ball 11 thereon, (hereinafter referred to as tee 12); sensor means 13 for detecting the passing (downswing) of a club head (not shown) for hitting the ball 11; a first camera 14 and a second camera 15; a control unit 16; a monitor 17; and a printer 18. The sensor means 13 is located behind the tee 12 with respect to the travel direction of the hit ball 11. The first camera 14 and the second camera 15 are disposed ahead of the tee 12 with respect to the travel direction of the ball 11 such that they are located a predetermined distance from the tee 12 and are apart from each other and face horizontally. The control unit 16 has trigger means for sending shutter signals for the hit ball 11 to the respective first and second cameras 14 and 15. When a detection signal is received from the sensor means 13, the trigger means sends shutter signals to the first and second cameras 14 and 15 at a proper timing such that an appropriate time lag is provided between the shutter signals sent to the first and second cameras 14 and 15. Reference letter M represents a mark printed on the surface of the ball 11. When measurement is performed by use of the present system, the ball 11 is set on the tee 12 in a state in which the mark M faces the side where the cameras 14 and 15 are present. The first and second cameras 14 and 15 are preferably CCD cameras each having a shutter speed of {fraction (1/10,000)} to {fraction (1/200,000)} second.

[0035] The sensor means 13 includes a pair of optical sensors, or a first sensor 13A and a second sensor 13B, which are disposed with at an interval m1 (70 mm) (see FIG. 2) and each of which is composed of a light-emitting element and a light-receiving element. The distance m2 between the tee 12 and the sensor means 13 is preferably approximately 40 mm. The distance m3 between the tee 12 and the first camera 14 and the distance m4 between the first and second cameras 14 and 15 preferably range from 30 to 300 mm and from 50 to 250 mm, respectively. The positional height of the first and second cameras 14 and 15 with respect to the golf ball 11 (placed on the tee 12) must be determined in consideration of the trajectory of the hit ball 11. For a certain site of measurement, a light 19 may be provided for illuminating the trajectory of the hit ball 11. Also, these cameras 14 and 15 may be equipped with respective strobes 20 (flashing means) which operate synchronously with shutters thereof. Each of the horizontal distances between the hit ball 11 on its trajectory and the first and second cameras 14 and 15 is preferably 200 to 600 mm.

[0036] The control unit 16, which is connected to the sensor means 13, the cameras 14 and 15 equipped with the respective strobes 20, the monitor 17, and the printer 18 (specific connections are not illustrated), includes the following:

[0037] (1) Control box

[0038] The control box includes the following:

[0039] a) Frame memory for recording photographed images

[0040] b) Image analysis unit

[0041] c) Timing control unit

[0042] Sensor control, shutter control, I/O

[0043] d) CPU unit

[0044] e) FDD (floppy disk drive), HDD (hard disk drive), or flash memory

[0045] (2) Software

[0046] Software for performing the following functions:

[0047] a) Calculation and display of head speed, initial velocity, launch angle (upward angle with respect to a horizontal line and sideward angle with respect to a reference line), backspin, and side spin

[0048] b) Calculation of trajectory and travel distance

[0049] c) Display of the following screens Divided screen (2 display areas for displaying the image of a ball and 1 display area for displaying measured values)

[0050] Launch angle distribution screen

[0051] Carry and/or total distance distribution screen

[0052] Trajectory screen

[0053] d) Accumulation of data

[0054] Next, a method which the present system employs in order to measure head speed, initial velocity, launch angle (upward angle with respect to a horizontal line), backspin, and side spin and to calculate travel distance will be described with reference to FIGS. 2 and 3. When the first and second sensors 13A and 13B detect the passage of a golf club head, the control unit 16 calculates time t1 required for a club head to pass between the sensors. Based on the measured time t1 and the distance between the sensors 13A and 13B, the control unit 16 calculates a head speed. Upon reception of a detection signal from the second sensor 13B, the control unit 16 outputs a trigger signal to each of the cameras 14 and 15 and to each of the strobes 20. In the present embodiment, a plurality of head speeds are previously measured. In operation, a delay time t2 and a shutter interval t3 are previously set in accordance with an applicable head speed selected from the previously measured head speeds. Further, an initial velocity is measured from a time which the hit ball required to pass through the region between the two cameras 14 and 15 and the distance between the two cameras 14 and 15.

[0055]FIG. 4 shows the screen of the monitor 17 on which images of the hit ball are displayed. The monitor screen 40 is divided into four display areas. A first display area 40A displays the side view of the hit ball 11 as obtained through the first camera 14. A second display area 40B displays the side view of the hit ball 11 as obtained through the second camera 15. A third display area 40C displays measured values. In the present system, the mark M formed on the surface of the golf ball 11 assumes the form of an isosceles triangle. The mark M is colored black or similar dark color such that the mark M stands out against the color of the ball surface.

[0056] In the present system, with respect to images appearing in the first and second display areas 40A and 40B (FIG. 4), outlines of the golf ball 11 displayed as a white portion are extracted from the black background by means of a binarizing method for digitizing the images into binary data (black/white). Subsequently, the mark M within each of the outlines of the golf ball 11 is extracted by means of a similar binarizing method.

[0057] After completion of the above-described processing, a main axis (a height-direction straight line bisecting the vertex angle) of the mark M is obtained; and the mark M is perpendicularly scanned from the main axis in order to obtain a change point at which the color changes from black to white. This scanning operation for searching a color-change point is performed along the main axis. As a result, lines respectively passing through two rows of change points; i.e., two sides, are obtained. Subsequently, base lines which perpendicularly intersect the median lines of the sides are set outside the black block (black mark); and scanning is performed from the base lines toward the block side in order to obtain the base. When the sides and the base are obtained, curve approximation is preferably employed in consideration of curvature of the spherical surface.

[0058] After a triangle; i.e., the mark M, is specified through the above-described image processing, three angular points 50 x, 50 y, and 50 z are determined from the sides and the base. Subsequently, the three-dimensional vectors of the three angular points 50 x, 50 y, and 50 z are obtained on the basis of the images appearing in the first and second display areas 40A and 40B, with the ball 11 being taken as a unit ball having a radius of 1. Based on the movement of the ball 11 from its position in the first display area 40A to that in the second display area 40B, the vector of the rotational axis of the ball 11 is obtained. Through a vector operation between the rotational axis vector and the position vectors of the respective points, the amount of rotation of the ball 11 is obtained. Based on the rotational axis vector and the rotation amount, the amounts of backspin and side spin of the ball 11 can be obtained. Also, a difference in vertical position of the golf ball 11 between the first display area 40A and the second display area 40B (FIG. 4) is measured. Then, based on the thus-measured difference in vertical position and the distance m4 (horizontal distance), the upward launch angle of the ball 11 can be obtained. Further, a travel distance can be calculated from the thus-obtained initial velocity, launch angle, backspin, and side spin.

[0059] In the present system, launch angle, backspin, and side spin are obtained by use of the mark M of an isosceles triangle formed on the surface of the golf ball 11. However, launch angle, backspin, and side spin may be obtained in a similar manner by use of a character or a mark of another shape provided on the surface of a golf ball.

[0060] Next, an example method of selecting a golf club by use of the present system will be described. In the system, the sensor means 13, the first camera 14, the second camera 15, the control unit 16, and the monitor 17 constitute actual hit data obtainment means; the control unit 16 and the monitor 17 constitute ideal data obtainment means; the control unit 16 constitutes comment producing means; and the control unit 16 and the printer 18 constitute printing means. In this case, the above-mentioned actual hit data obtainment means obtains at least one of head speed and hit-ball data when a golfer hits a golf ball with a golf club. The above-mentioned ideal data obtainment means obtains ideal hit-ball data of the golfer on the basis of said at least one of head speed and hit-ball data obtained by use of the actual hit data obtainment means. The above-mentioned comment producing means producing a comment for the golfer on the basis of said at least one of head speed and hit-ball data obtained by use of the actual hit data obtainment means. This comment enables the golfer to clearly know the swing characteristics of the golfer and the effects of a selected golf club for trial hit. The above-mentioned printing means prints at least one selected from the head speed and hit-ball data obtained by use of the actual hit data obtainment means; the ideal hit-ball data obtained by use of the ideal data obtainment means; and the comment obtained by use of the comment producing means. The printed data or comment enables the golfer to easily check the swing characteristics of the golfer and the effects of a selected golf club for trial hit.

[0061] (1) First, a golfer hits a golf ball with a golf club which the golfer has used up to now and which is therefore familiar to the golfer. At this time, the actual hit data obtainment means obtains the head speed, initial velocity, launch angle, backspin, side spin, and travel distance of the hit ball in the above-described manner (step a). These values are displayed on the monitor 17 (step e). Each of these values may be an average value or a maximum value obtained through hitting of a plurality of balls.

[0062] (2) Subsequently, the ideal data obtainment means obtains an ideal initial velocity, launch angle, backspin, side spin, and travel distance of the golfer on the basis of the head speed obtained by the actual hit data obtainment means (step b). Specifically, the calculation unit 16 calculates the ideal initial velocity, launch angle, and backspin from the head speed in accordance with the following expressions. The ideal side spin is set zero. The ideal travel distance is calculated from the ideal initial velocity, launch angle, backspin, and side spin in accordance with a predetermined expression. These values are displayed on the monitor 17 (step e).

Ideal initial velocity=F×head speed+G

[0063] F: predetermined coefficient

[0064] (e.g., a predetermined value between 1.3 and 1.5)

[0065] G: predetermined constant

[0066] (e.g., a predetermined value between −0.5 and 0.5)

Ideal launch angle=H×head speed+I

[0067] H: predetermined coefficient

[0068] (e.g., a predetermined value between −0.4 and −0.2)

[0069] I: predetermined constant

[0070] (e.g., a predetermined value between 25 and 31)

Ideal backspin=J×head speed+K

[0071] J: predetermined coefficient

[0072] (e.g., a predetermined value between −50 and −30)

[0073] K: predetermined constant

[0074] (e.g., a predetermined value between 3700 and 5100)

[0075] (3) On the basis of at least one of head speed and hit-ball data obtained in (1) above and the ideal hit-ball data obtained in (2) above, a guideline is provided for showing a way of modifying the golf club used in (1) above in order to obtain hit-ball data close to the ideal hit-ball data obtained in (2) above (step C). Examples of the guidelines include those described in (i) to (iv) above. These guidelines are displayed on the monitor 17 (step e).

[0076] Further, the specifications of an ideal golf club which enables obtainment of hit-ball data close to the ideal hit-ball data obtained in (2) above are provided on the basis of the specifications of the golf club used in (1) above and the above-described guide lines. The thus-provided specifications are displayed on the monitor 17.

[0077] (4) In a manner similar to that used in (1) above, the actual hit data obtainment means obtains the head speed, initial velocity, launch angle, backspin, side spin, and travel distance when the golfer hits a golf ball with (the selected golf) club. When two or more golf clubs are selected, the above-described values are obtained for each golf club. These values are displayed on the monitor 17 (step e). Each of these values may be an average value or a maximum value obtained through hitting of a plurality of balls.

[0078] (5) Subsequently, the comment producing means produces a comment on the golf club that the golfer used first. The comment is produced on the basis of the head speed, backspin, and side spin obtained in (1) above. Further, a comment on the golf club for trial hit that the golfer has selected is produced on the basis of the backspin, side spin, and travel distance obtained in (4) above. Specifically, a sentence is prepared for a certain range of each value as described below and stored in the control unit 16. When a value falls within the corresponding range, the corresponding sentence is selected. These sentences for the respective values are connected automatically so as to produce a comment.

[0079] The head speed obtained in (1) falls within a predetermined range: “HEAD SPEED IS SLIGHTLY EXCESSIVE, AND SR, S FLEX, OR SIMILAR TYPE IS PROPER.”

[0080] The backspin obtained in (1) is slightly greater than ideal backspin: “BACKSPIN IS SLIGHTLY EXCESSIVE.”

[0081] The side spin obtained in (1) is close to ideal side spin: “TRAJECTORY IS SUBSTANTIALLY STRAIGHT.”

[0082] These sentences are connected so as to obtain a comment “HEAD SPEED IS SLIGHTLY EXCESSIVE, AND SR, S FLEX, OR SIMILAR TYPE IS SUITABLE. BACKSPIN IS SLIGHTLY EXCESSIVE, BUT TRAJECTORY IS SUBSTANTIALLY STRAIGHT” as a comment on the golf club that the golfer used first.

[0083] The backspin obtained in (4) has decreased from the backspin obtained in (1) by a predetermined amount and approaches ideal backspin: “BACKSPIN DECREASES TO A LEVEL CLOSER TO THE PROPER LEVEL.”

[0084] The side spin obtained in (4) is substantially equal to the backspin obtained in (1) and is close to the ideal side spin: No comment.

[0085] The travel distance obtained in (4) has increased considerably as compared to that obtained in (1): “TRAVEL DISTANCE HAS BEEN EXTENDED GREATLY.”

[0086] These sentences are connected so as to obtain a comment “BACKSPIN DECREASES TO A LEVEL CLOSER TO THE PROPER LEVEL. SIDE SPIN HAS NOT CHANGED, BUT TRAVEL DISTANCE HAS BEEN EXTENDED GREATLY.” as a comment on the golf club for trial hit that the golfer has selected.

[0087] (6) The printer 18 prints, on a predetermined sheet, the head speed, initial velocity, launch angle, backspin, side spin, and travel distance obtained in (1) above; the ideal initial velocity, launch angle, backspin, side spin, and travel distance obtained in (2) above; and the head speed, initial velocity, launch angle, backspin, side spin, and travel distance of the selected golf club obtained in (4) above. FIG. 5 shows an example sheet produced by the printing means. In FIG. 5, the term “MY CLUB” means the golf club with which the golfer hit golf balls in (1) above; and the term “BALL SPEED” means initial velocity.

[0088] (7) The specifications of the ideal golf club provided in (3) above are output on a post card paper and/or a floppy disk. Further, the specifications may be output to other types of information recording media (CD, MO, etc.).

[0089] As described above, the golf club selecting method according to the present invention enables a golfer to properly select a golf club suitable for the golfer after actually hitting a ball with the golf club, even when none of golf clubs on the market is suitable for the golfer, and a custom made club is suitable for the golfer. 

What is claimed is:
 1. A method for selecting a golf club suitable for a golfer, comprising the steps of: (a) obtaining at least one of head speed and hit-ball data when a golfer hits a golf ball with a golf club; (b) obtaining ideal hit-ball data of the golfer on the basis of said at least one of head speed and hit-ball data obtained in step (a); (c) providing a guideline for showing a way of modifying the golf club used in step (a) in order to obtain hit-ball data close to the ideal hit-ball data obtained in step (b), the guideline being provided on the basis of said at least one of head speed and hit-ball data obtained in step (a) and the ideal hit-ball data obtained in step (b); (d) obtaining at least one of head speed and hit-ball data when the golfer hits a golf ball with a golf club for trial hit which matches, to the extent possible, the guideline provided in step (c); and (e) displaying one or more items selected from said at least one of head speed and hit-ball data obtained in step (a), the ideal hit-ball data obtained in step (b), the guideline provided in step (c), and said at least one of head speed and hit-ball data obtained in step (d).
 2. A method for selecting a golf club according to claim 1, further comprising the step of providing specifications of an ideal golf club which enables obtainment of hit-ball data close to the ideal hit-ball data obtained in step (b), the specifications being provided on the basis of specifications of the golf club used in step (a) and the guideline provided in step (c).
 3. A method for selecting a golf club according to claim 2, further comprising the step of printing out the specifications of the ideal golf club on a sheet of paper that is to become a post card.
 4. A method for selecting a golf club according to claim 2, further comprising the step of outputting the specifications of the ideal golf club to a floppy disk.
 5. A method for selecting a golf club according to claim 1, wherein in step (a), the golfer hits a golf ball by use of a golf club which the golfer has used up to now.
 6. A method for selecting a golf club according to claim 1, wherein the hit-ball data include at least one selected from initial velocity, launch angle, backspin, side spin, and travel distance of a hit ball. 